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Driver List Database code 16 December 2019 Footnotes 10 August 2016

• Step-up drivers • Low voltage step-down drivers

• Mains drivers • User interface & PWM drivers

Drivers not yet added 3 March 2012 Links 28 February 2012

Why use a driver? 20 February 2010

Driver types overview 15 September 2010

LED Driver List – step-up LED drivers (boost and boost/buck)

An O-ring, Tailcap & Silicone Grease List is also available.

Video Foundry/Aqualab does not sell any of these drivers. Links are provided to resellers. The short URL for this list is www.videofoundry.co.nz/driverlist. See the bottom of the page for my email address. If you're just a spam bot looking for fodder, spam the hell out of these spammers' addresses: spammer address 1, spammer address 2, spammer address 3. They deserve a taste of their own spam.

Note that some sellers are more reliable than others. Inclusion of particular resellers in this list is not an endorsement of them as businesses. Note that Fasttech closed in December 2022 but the drivers are still included for reference.

Jump to: Footnotes & Instructions | Schottky diodes.

65 drivers found. Listed by price.

Notes

Footnotes & Instructions

Notes on AMC7135 linear regulator (click to expand/contract)

The AMC7135 (datasheet) is a linear regulator, which means it acts like a variable resistor changing its value to try to keep the current constant. Like a resistor, any dropped voltage is burnt off as heat. Boards include a polarity protection diode and can easily be PWM-driven for lower modes.

V_in must be at least 0.12 V above V_f of LED to stay in regulation, although they drop out of regulation quite gracefully, not suddenly. The graph in the AMC7135 datasheet (Jan 2006) has the 0.1 and 1 volt vertical lines missing. Each AMC7135 provides constant current, about ¹/₃ amp (actually 300-380 mA depending on particular version; I've generally assumed 330-335 mA for above listings). Boards come with one to eight AMC7135s, and single mode up to 20 mode. Boards can be paralleled to give greater output, or connected with one multimode board controller providing the modes for several boards.

The AMC7135 is very efficient when input voltage is close to output voltage but not particularly good when input voltage is significantly higher. Average efficiency for 3x NiMH or 1x Li-ion can be well over 90% with an LED with the right V_f. Test results and discussion for 3 and 4 chip boards.

Since the AMC7135 just burns off excess input volts as heat, the more volts fed into them the hotter they'll get. One guy claimed that his got so hot they slid right off the board (ie, >183-190 °C melting range of 60/40 solder). The AMC7135 has built-in thermal protection (which will cause dropouts or a flickering effect if it gets too hot) but the multi-mode control chips used on the multi-mode boards are much less rugged. (And here.) If using with an input voltage above 4.5 V or so you can expect them to get hot!

To get multiple modes typical microcontrollers used are the Atmel ATtiny13 (or 13A or 13V) and the Microchip PIC12F629. These both have a 5.5 V maximum, while the AMC7135 linear regulator has a 6.0 V maximum. This means that multimode drivers will have a slighty lower maximum voltage than single mode boards.

Tip 1: To get reliable operation at low voltages, especially with only one AMC7135 chip being used, you may need to short out (and maybe remove) the polarity protection diode(s)*. This is because the AMC7135 in series with a polarity protection diode needs a minimum 2.7 V + 0.6 V (silicon diode) = 3.3 V to stay in regulation. The V_f of LEDs at 330-350 mA can easily be quite a bit lower than 3.3 V so will not be running in regulation. Note that if a germanium or Schottky diode was used the drop could be as low as 0.3 V instead of 0.6 V.

* However, I found with one multimode board this caused the board to go unstable (don't know exactly why) but I found that inserting a small value resistor instead of the diode was enough to get the driver stable again. Because the drive current through that point in the circuit is so low (6 mA for mine) there's very little voltage drop across the resistor - much less than across the diode - so it still serves the purpose of saving ~0.6 V.

Tip 2: If the input voltage is too high you may be able to use another LED in series with the board to drop the voltage - it beats burning it all off as heat. (The set current is <1 mA for single mode boards so both LEDs will get practically identical current. Diagrams and much discussion of use with multiple Seoul P7s and multi-mode boards.) More than one extra LED appears to be not a good idea for use with the lower modes of multi-mode boards since the V_f of the extra LEDs decreases too much at the low current to protect the driver from the battery voltage. (Many of the multi-mode boards have a capacitor on the output.) Flashing modes appear unsuited to this technique.

AMC7135-based driver options are discussed here, or an inexpensive multimode AMC7135 driver here.

Notes on PT4105 and alternative driver chips (PT4115, AX2002, CL6807) (click to expand/contract)

PT4105 (datasheet):

Production of this driver IC - as used in the Kennan and MR16 base drivers described above - has been terminated. The manufacturer doesn't even have a publicly displayed link to the datasheet any more, which is the weirdest part of it. This from Micro Bridge (now removed from their site; try to ignore the punctuation and spacing):

The PT4105 which the manufacture has already officially stopped producing,and the subsequent instead item is the PT4115,AX2002 and FP6101 Also,The PT4115,AX2002 and FP6101 has superior performance over ,wider input range and more current than the PT4105.

PT4115 (datasheet):

While I look forward to the PT4115 being available in low cost LED drivers (by its numbering the apparent successor to the PT4105), I note that it needs an input of at least 8 V (and has under voltage lock out at 6.8 V), so isn't nearly as well suited to low voltage torches as the PT4105 was. It will, however, have its uses for 3x Li-ion torches and automotive purposes. The chip has a DIM pin which gives it the ability to very easily be dimmed. Efficiency is about 80-82% for 1 LED, up to 93% for 3 LEDs, and apparently up to 98% for 7 LEDs. Maximum output current 1.2 A.

AX2002 (datasheet):

This driver chip from AXElite looks extremely interesting. It will accept a minimum 3.6 V input and has a maximum switched current of 2.5 A, although it tends to overheat at more than 2 A. It includes thermal protection (140°C), over current protection, short circuit protection, and has a PWM control circuit. Its efficiency is good too, with an output of 2 A @ 5 V it's an impressive 91% efficient (with 12 V input). Driving a Cree XR-E at 1 amp will give an efficiency of about 87-88% (with 12 V input). Efficiency is not quite as good at low currents with a single LED, dropping under 80%.

AX2002 drivers can also easily be configured as a constant voltage power supply. The load is connected straight to ground and the 0.25 V reference voltage is used to control a voltage divider with a couple of moderately high value resistors to give a fixed multiple of 0.25V at V_OUT.

For example, for 5 V, 5 = 20 * 0.25, so a 10 kΩ resistor is placed between ground and FB (the feedback pin), and a 190 kΩ resistor between FB and V_OUT (making the total of those resistors between V_OUT and ground of 200 kΩ).

When used in this way, to give stability the current through the resistors probably just needs to be comfortably greater than the feedback pin bias current of (0.1 µA typical, 0.5 µA maximum). If two exact resistor values for the voltage divider are not available it's easiest to use a single resistor for the sense resistor (between ground and FB), while the other value (between FB and V_OUT) uses two resistors in series or parallel. For series, one of those two resistors will be as close as possible to the desired value, and just under it, while the other will be a much smaller resistor to tweak the total resistance up for the output voltage wanted. For parallel, the main resistor is just over the actual value wanted while the other resistor with about ten times the resistance tweaks the total resistance down. If that resistor is getting into megaohms you should probably revise your values.

Some AX2002 drivers (such as DX 3256 sadly no longer an AX2002 driver) come with a 1 A Schottky diode, which will need to be changed if increasing the output current over 1 A. See the Schottky diode notes below for links.

AX2003 (datasheet):

The AX2002 also has a big brother, the AX2003, which has a maximum switched current specification of 4 amps – easily enough to drive a Seoul P7, or a Cree MC-E with the dice in parallel. No drivers with the AX2003 are presently known. The spec sheets of the AX chips could do with a few more graphs showing how constant the output current is, etc.

FP6101 (datasheet): Not an LED driver.

CL6807 (datasheet):

Chinese LED driver, 1 A maximum output current, 6-35 V input, 0.1 V high side sense voltage. Claims to be able to provide up to 35 W output power. Dimmable with 0.5-2.5 V PWM signal.

So there are some nice driver chip options, but it still leaves a gap of a high efficiency, really low voltage, low current driver.

Notes on Schottky diodes (click to expand/contract)

Schottky diodes are diodes that have a low voltage drop across them. 0.3 V is a typical figure, compared to around 0.60-0.65 V for a typical silicon diode. This makes Schottky diodes good for rectifiers and LED drivers where high efficiency is required. Drivers that use the AX2002 such as DX 3256 can easily be modified for higher output current but the Schottky diode needs to be replaced if the output current is to exceed 1 A.

Inexpensive Schottky diodes are available from these sources:

• These MR16 drivers have four 1 A (SS14) Schottky diodes on them used for the rectifier plus another for the driver (links jump to driver info in table above):
  • DX 13553.
  • DX 13555.
  • DX 13557.
• SR260 60V 2A Schottky Diodes Set (10 pcs).
• Common Use Axial Schottky / Fast Recovery / Fast Switching / Rectifier Diodes (220 piece pack):
  • 20 x 1N4001 Rectifier diodes
  • 20 x 1N4004 Rectifier diodes
  • 20 x 1N5399 Rectifier diodes
  • 20 x 1N4007 Rectifier diodes
  • 50 x 1N4148 Fast switching diodes
  • 10 x 1N5408 Rectifier diodes
  • 20 x 1N5819 Schottky barrier diodes
  • 10 x 1N5822 Schottky barrier diodes
  • 20 x FR107 Fast recovery diodes
  • 20 x FR104 Fast recovery diodes
  • 10 x FR207 Fast recovery diodes
• 1N5822 3 Amps 40V Schottky Barrier Rectifier Diodes 20-pack (if you want to risk that site).

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